fix: enhance web search functionality with proxy support (#1823)

* fix: enhance web search functionality with proxy support

- Remove unnecessary blank line in README.md
- Add missing closing details tag in both README.md and README_zh.md
- Add proxy support to the web search engine configuration in config.lua
- Ensure the web search function uses the proxy setting when available in init.lua
- Fix a potential nil access in the response body format check in config.lua

Signed-off-by: 范立洲 <fanlizhou@yunqilaohe.com>

* [pre-commit.ci lite] apply automatic fixes

---------

Signed-off-by: 范立洲 <fanlizhou@yunqilaohe.com>
Co-authored-by: 范立洲 <fanlizhou@yunqilaohe.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

lua/avante/config.lua

@@ -47,6 +47,7 @@ M._defaults = {
   },
   web_search_engine = {
     provider = "tavily",
+    proxy = nil,
     providers = {
       tavily = {
         api_key_name = "TAVILY_API_KEY",

lua/avante/llm_tools/init.lua

@@ -212,6 +212,7 @@ end
 ---@type AvanteLLMToolFunc<{ query: string }>
 function M.web_search(opts, on_log)
   local provider_type = Config.web_search_engine.provider
+  local proxy = Config.web_search_engine.proxy
   if provider_type == nil then return nil, "Search engine provider is not set" end
   if on_log then on_log("provider: " .. provider_type) end
   if on_log then on_log("query: " .. opts.query) end
@@ -223,7 +224,7 @@ function M.web_search(opts, on_log)
     return nil, "Environment variable " .. search_engine.api_key_name .. " is not set"
   end
   if provider_type == "tavily" then
-    local resp = curl.post("https://api.tavily.com/search", {
+    local curl_opts = {
       headers = {
         ["Content-Type"] = "application/json",
         ["Authorization"] = "Bearer " .. api_key,
@@ -231,7 +232,9 @@ function M.web_search(opts, on_log)
       body = vim.json.encode(vim.tbl_deep_extend("force", {
         query = opts.query,
       }, search_engine.extra_request_body)),
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.post("https://api.tavily.com/search", curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)
@@ -244,11 +247,13 @@ function M.web_search(opts, on_log)
     for key, value in pairs(query_params) do
       query_string = query_string .. key .. "=" .. vim.uri_encode(value) .. "&"
     end
-    local resp = curl.get("https://serpapi.com/search?" .. query_string, {
+    local curl_opts = {
       headers = {
         ["Content-Type"] = "application/json",
       },
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.get("https://serpapi.com/search?" .. query_string, curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)
@@ -261,11 +266,13 @@ function M.web_search(opts, on_log)
     for key, value in pairs(query_params) do
       query_string = query_string .. key .. "=" .. vim.uri_encode(value) .. "&"
     end
-    local resp = curl.get("https://searchapi.io/api/v1/search?" .. query_string, {
+    local curl_opts = {
       headers = {
         ["Content-Type"] = "application/json",
       },
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.get("https://searchapi.io/api/v1/search?" .. query_string, curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)
@@ -283,11 +290,13 @@ function M.web_search(opts, on_log)
     for key, value in pairs(query_params) do
       query_string = query_string .. key .. "=" .. vim.uri_encode(value) .. "&"
     end
-    local resp = curl.get("https://www.googleapis.com/customsearch/v1?" .. query_string, {
+    local curl_opts = {
       headers = {
         ["Content-Type"] = "application/json",
       },
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.get("https://www.googleapis.com/customsearch/v1?" .. query_string, curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)
@@ -299,12 +308,14 @@ function M.web_search(opts, on_log)
     for key, value in pairs(query_params) do
       query_string = query_string .. key .. "=" .. vim.uri_encode(value) .. "&"
     end
-    local resp = curl.get("https://kagi.com/api/v0/search?" .. query_string, {
+    local curl_opts = {
       headers = {
         ["Authorization"] = "Bot " .. api_key,
         ["Content-Type"] = "application/json",
       },
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.get("https://kagi.com/api/v0/search?" .. query_string, curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)
@@ -316,12 +327,14 @@ function M.web_search(opts, on_log)
     for key, value in pairs(query_params) do
       query_string = query_string .. key .. "=" .. vim.uri_encode(value) .. "&"
     end
-    local resp = curl.get("https://api.search.brave.com/res/v1/web/search?" .. query_string, {
+    local curl_opts = {
       headers = {
         ["Content-Type"] = "application/json",
         ["X-Subscription-Token"] = api_key,
       },
-    })
+    }
+    if proxy then curl_opts.proxy = proxy end
+    local resp = curl.get("https://api.search.brave.com/res/v1/web/search?" .. query_string, curl_opts)
     if resp.status ~= 200 then return nil, "Error: " .. resp.body end
     local jsn = vim.json.decode(resp.body)
     return search_engine.format_response_body(jsn)